His huge medical collection is now housed at the Hunterian Museum at the Royal College of Surgeons.

It includes his colourful notes describing a man who arrived at St George’s Hospital, in 1786, with a hard swelling on his lower thigh.

“It appeared to be a thickening of the bone, it was increasing very rapidly… On examining the diseased part, it was found to consist of a substance surrounding the lower part of the thigh bone, of the tumour kind, which seemed to originate from the bone itself.”

Mr Hunter amputated the man’s leg and he recovered briefly for four weeks.

“From this time he began to lose flesh and sink gradually, his breathing more and more difficult,” the notes continued.

The patient died seven weeks after the operation and an autopsy discovered bony tumours had spread to his lungs, the lining of the heart and on the ribs.

More than 200 years later, the samples fell under the gaze of Dr Christina Messiou.

She said: “Just looking at the specimens, the diagnosis of osteosarcoma came very quickly to me and John Hunter’s write up was amazingly astute and fits with what we know about the behaviour of the disease.

“The large volumes of new bone formation and the appearance of the primary tumour are really characteristic of osteosarcoma.”

She went to get a second opinion from her colleagues at the Royal Marsden in central London.

And in an out-of-hours session at the hospital they used modern day scanning technology to confirm the centuries old diagnosis.

Dr Messiou, whose speciality is sarcoma, told the BBC: “I think his diagnosis is really impressive and in fact his management of the patient followed similar principles to what we would have done in the modern day.”

But she says the exciting stage of the research is still to come.

They are now going to compare more of Hunter’s historical samples with contemporary tumours – both microscopically and genetically – to see if there are any differences.

Dr Messiou told the BBC: “It’s a study of cancer evolution over 200 years and if we’re honest we don’t really know what we’re going to find.

“But it would be interesting to see if we can link lifestyle risk factors with any differences that we see between historical and current cancers.

“So we’ve got big ambitions for the specimens.”

Writing in the British Medical Journal, the Royal Marsden team apologised for delay in analysing the samples from 1786 and the obvious breach of cancer waiting times, but point out their hospital was not built until 1851.